Theranostics 2013; 3(1):3-10. doi:10.7150/thno.4621
Innate Immunity Derived Factors as External Modulators of the CXCL12 - CXCR4 Axis and Their Role in Stem Cell Homing and Mobilization
1. Stem Cell Biology Program at the James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky, USA.
2. Department of Physiology Pomeranian Medical University, Szczecin, Poland.
Ratajczak MZ, Serwin K, Schneider G. Innate Immunity Derived Factors as External Modulators of the CXCL12 - CXCR4 Axis and Their Role in Stem Cell Homing and Mobilization. Theranostics 2013; 3(1):3-10. doi:10.7150/thno.4621. Available from http://www.thno.org/v03p0003.htm
The α-chemokine CXCL12 (stromal derived factor-1; SDF-1) and its corresponding GαI protein-coupled CXCR4 receptor axis play an important role in retention of hematopoietic stem progenitor cells (HSPCs) in bone marrow (BM) stem cell niches. CXCL12 has also been identified as a strong chemoattractant for HSPCs and implicated both in homing of HSPCs to BM after transplantation and in egress of these cells from BM into peripheral blood (PB). However, since CXCL12, as a peptide, is highly susceptible to degradation by proteolytic enzymes, its real biological availability in biological fluids may be somewhat limited. In this review, we will present data demonstrating that the CXCL12-CXCR4 axis is positively modulated by innate immunity-derived several external factors, ensuring that even low (near threshold) doses of CXCL12 still exert a robust chemotactic influence on HSPCs.
Keywords: CXCR4, CXCL12, SDF-1, C3a, LL-37, stem cell mobilization, stem cell homing.